There are no historical records as to which came first Japanese or Chinese
tea staining. However, if you follow the general patterns of east Asian
cultures, there is a general tendency for tea staining to flow from China
into Korea and then Japan. This is because tea was first drank and
researched on by the Chinese.

Tea like many other cultures from China were first imported into Japan
during Tang dynasty in large quantities. They came through Korea just like
the art of pottery.

Tea stained clothing items were not considered that avant garde in Chinese
civilizations starting from Tang. This was because of the greater
fascination for silk and dyeing using flower dyes and other forms of dyes
instead. Tea staining was only appreciated by a small minority.

Although all tea plants originate from the species of camelia sinensis, only
green tea powder is really suitable for dying as green tea powder due to its
manufacturing process is able to retain the green color for dying purposes.
Oolong tea for example having gone through fermentation and pan frying has
lost most of the properties of green and they are charred dry brittle leaves
to begin with.

Thus, green tea which really originates from central China was utilized as a
form of dye in that region. Central China would mean Hangzhou, Shanghai,
Suzhou etc. They are used to dye fabrics like handkerchief, clothing,
scarves etc.

Then this spread to Korea and Japan. Korea and Japan developed their own
types of tea staining and they developed the art further. It won more
acclaim in those countries. However, silk and other dyes were more popular
still as red, yellow, orange colours were still more popular than say green.

Tea staining is a dying art in China and barely surviving in Korea. This is
because of the onset of modern techniques of mass manufacturing process for
dyeing. However, it is still being advanced in Japan in certain towns which
are now famous for tea staining methods. They include certain towns in
Kyushu the southern part of Japan where green tea is extensively grown and
certain parts near Tokyo. Tourists can visit these places and buy tea
stained items like handkerchief scarfs etc.

The process is simple. Green tea is made into a powder form. And they are
concentrated and mixed in a solution. Hot water is also mixed into the
solution.
Clothes are then dipped into a wooden bucket with the dye. The parts that
are not meant to be dyed are carefully tied up to avoid the mixture. And
then the dyed clothes are left out to dry. The colours then stays permanent.